Late summer flushes a lazy warmth across the plain of Marathon, and the smell of death sits strange over the tops of the wildflowers. Until this morning, when ugly spear-points began their work in earnest, any hope of a Greek victory must have burned dimly - but what was impossible is now done. Ten thousand well-armed Athenians have met a Persian contingent many times their strength. They have charged the enemy: a mile across open terrain, deluged with arrow-fire, ululating their battle-cry, unsupported by cavalry. These men were all that stood between their homes and an army that knew no prior defeat. Through daring, discipline and a turn of desperate cunning, they have broken their enemy, proving that even in the face of Persian numbers, resistance is possible. Greek victories over the coming decades - Thermopylae, Salamis, Plataea - will all be owed to this first triumph. Millennia later, so will almost every imprint that Classical Greek culture has left on the world. Without Marathon, the rise of Athens ends today - four centuries early - and in ruin.

Having fled to their boats, the Persians are crawling hopelessly round the peninsula to resume their attack from its opposite coast. The Greeks march to intercept them and conclude the matter. The battlefield is empty, save for the groans of the dying - but a long distance away, a lone soldier still trades sandal-slaps and heavy breaths one-for-one. A hard day’s killing is already behind him, as are twenty miles of leaf-blond Mediterranean scrub. The heat is excruciating. The first two-thirds’ running have been uphill. He is close to collapse, but his task is more important than his tiredness.

Back at home, an entire city waits to learn its fate. He is running to tell them. In slow hours, Athens crawls into his view. The Persian Empire can be - has been - defeated. The world has changed. They must know. But he’s at the very end of his reserves. He passes outlying farms, stables. By the time he reaches the city he bled to defend, he’s empty. He sees silhouettes. People, standing. Listening. There’s a lot to tell, but already his life is fading away from him. He gasps a single word, and dies in the dust. Nenikekamen. “We won”.

It is enough.

Meet Pheidippides: our connection between the modern marathon and its capitalised namesake. His story’s an old one, and old stories don’t survive by accident. Is his tale powerful simply because he ran far? Because he had good news to deliver? Not really. It is powerful because in spite of my rather purple re-telling, the narrative content can be delivered in a few syllables:

No matter how told, every part of the story works to deliver its message. Nenikekamen itself - that elated, exasperated, exhausted triumph - is a distillation of meanings already mixed into the plot. A colossal existential threat, a long and tiring journey, a brutal struggle to survive, and those final five syllables: the images convey the narrow margin of the Greek army’s success as much as that of the messenger’s. Pheidippides’ distillation of the story to Nenikekamen, backed by his final journey, speaks also to the singularity of purpose on the Greek half of the field: the determination which wrought that victory is just as pertinent as its result. We haven’t forgotten this narrative, because it is gemlike. Every part of it reflects onto every other part, and wherever the reader’s focus, whatever the single aspect remembered, one sees a variation of the same clear message.

This is the beauty of a good story told in a narrow and unforgiving medium. The tale of Pheidippides can be compressed until barely anything remains, without losing its shape or the impact it has on those who receive it. It can be told in print, in song, as a bar-room anecdote or a ballet. Furthermore, it is itself a tale of re-telling: of how a powerful message can survive the harshest crucibles of medium, the signal loss in this case supplied by the physical degradation of the messenger. How better - indeed, how else - to describe an era-shaping battle in a way that transmits its power and gravity undiminished? The purity in this story-of-a-story is so potent as to be unaffected by its imperfect vehicle.

The telling of all spoken-word stories is in its rawest form a negotiation of the same challenge. They must take something vast or strange or complex, and describe it within the enforced simplicity of speech. To stay with the Marathon example, war is rich and vague in the spread of detail available to its chroniclers: a nuanced account draws on context, location, identity, strategy, fear, surprise, treachery, anguish, loss, cowardice and courage, all illustrated with stark visuals, smells and sounds. However, filtered through the hundred generations between Marathon and today, the battle’s relevance is binary: who won, who lost. The spoken word endures only through the willing efforts of its audience, and said efforts are invariably directed at those stories whose retelling is simple and relevant. Marathon’s tale could be remade in a hundred different ways and not lose its beating heart. It speaks to us from a world we will never know, yet we hear something within it that we recognise from our own essence.

Audiences are ruthless with their receptivity to the human voice, and not just in today’s climate of a wider ruthlessness around cultural consumption. Sound is ephemeral, and rarely gets more than one chance to reach its target, so unlike print, the spoken word must be consumed at its author’s pace - unlike a reader, a listener cannot easily flick back by three paragraphs to retrieve missed detail. Given that a spoken story is a transmission not of sounds to the ear but of meaning to the mind, it cannot work unless it grips the full attention of the listener throughout.

And there’s less room to flood the senses with entertaining imagery. Lavish visuals are possible, but they must be encoded in phrasing, pauses, music and ambient noise. Each character’s face, figure and body-language must be clumsily described, obliquely implied, or abandoned altogether. The same restrictions apply to costume, colour and scenery. Smell, taste and touch - all easy enough to infer using the broad channel of video - are nigh-impossible. Everything beyond the words themselves must be broken down into semantic components, re-parsed in audio, smuggled through the subconscious half of human hearing, and reconstructed in someone else’s imagination. Yet with all this crowded into the message, its content must still speak to people, or else be immediately forgotten. A spoken story, like Pheidippides’ message, is built to transit a narrow medium with its soul intact.

I’ve mentioned three ways of handling unspoken information in spoken stories: description (just say it), inference (drop hints) and abandonment (leave it out). The former and latter extremes are necessary to some extent: where a certain piece of exposition is core to the narrative, it’s often best to get it out of the way. However, in drama, the channels of communication are restricted to dialogue rather than narration. Dialogue renders exposition ugly and awkward, because real speech almost never explains anything from first principles. To use characters as plot-conduits is to have them break character.

So what about that elusive middle approach, implication? This can be an incredibly effective way of compressing the information we’re trying to communicate. Here’s an example from our own script:

Look at you. You can’t even touch me. You’re not even looking at me! What is it? What’s so wrong with me that you can’t stand the sight of me?

Consciously, the listener processes an emotional statement: distress, disgust, anger. Emotional impact is satisfying to audiences, who respond to entertainment. But there’s more information loaded into this line. By having the character verbally react to a physical movement, their speech sketches the body language and choreography of the scene. This allows the listener’s imagination to build a picture of the action while they’re concentrating on the dialogue’s dramatic impact. It’s narrative compression at work: smuggling visual information through the auditory channel, to be silently reconstructed inside the listener’s mind like a ship in a bottle. It’s been said that the best visuals are to be found on the radio. At the risk of sounding smug, that doesn’t happen by accident. The reality of a restrictive medium is that each word does more work and carries more weight.

I’ve so far neglected to mention the other problem with Pheidippides’ tale. It’s a lie. The story sprung up hundreds of years after the fact, and is most likely a conflation of two much older accounts. In one of these, Pheidippides travels a much greater distance (at a slower pace) to seek Spartan help before the battle, and in another, set shortly afterwards, the battle-weary Greeks march to the coast in order to see off the last riposte of the Persian navy, and so seal their victory. A clutch of loosely-told, vaguely truthful, similar messages have been compressed into one elegant falsehood, simply because the lie is a better story.

The process of constant revision is almost universal to spoken-word narratives, because they have both the evolutionary pressure to adapt and the fluidity of content to make this possible. Their structure is not rigid or recorded as in print. This mutability, rather than degrading a ‘perfect’ original, acknowledges and addresses the necessity of imperfection and the changeable nature of the audience, refreshing old stories for each new generation of listeners. As soon as a story has been untethered from the importance of accurate recall, its evolutionary journey can lead it to express far more satisfying narratives.

Consider a different question in the same context. A modern, English-speaking audience listens to an Ancient Greek story. Translation is mandatory; a narrative doesn’t work if no-one understands it. But what kind of modern English to use? There is no “default” dialect in any language. When handling the ancient world, Hollywood tends toward upper-crust, early 20th-century British or New England. This is partly because the received dialect’s pre-war habitat chimes nicely with a useful atmosphere of uncomplicated heroism: in Ridley Scott’s Gladiator, the linguistic quality of Maximus’ speeches can be radiocarbon-dated to around half-past-Robert Falcon Scott. It also owes something to the medium’s inherited insecurities: just as early photographs mimicked oil paintings, when the film world’s first traditions were established, its accents clung with varying consistency to the cut-glass conventions of the stage.

But just as importantly, to a modern audience, this dialect is chronologically and culturally distant from our own, without major loss of understanding. Hearing voices that sound “old-fashioned” is what reminds us to accept the unfamiliarity of the fictional world we’re experiencing. The empathy-cost of that distance can be a worthy trade when compensated by emotionally informative visuals, but in a voice-only medium it can dry all feeling from a production. And what about similarity? Audiences must be able to distinguish characters from each other, and heavy-breathing Fakespearian English is surprisingly samey when you close your eyes and listen. Without the visual information of face and costume, how should one illustrate the relationships between characters? Would Mycenaean Greeks and Trojans have spoken in the same accent? Should family groups inflect similarly to each other but differently to non-family members?

By changing the medium without adding to the message, we can lose information rather than preserving it. Maybe, at some point in the Marathon story’s adolescence, the fictional Pheidippides said five sentences before expiring instead of one word. If so, we might describe that version as ‘closer’ to the legend’s origin, but by speaking to our feelings, the one-word revision would still tell us more about the importance and intensity of the preceding battle. Where they help an audience to engage with a story’s core, additions and adaptations may render a re-telling more truthful, not less.

Our source text - The Odyssey - is one of the archetypal oral-tradition narratives. The patchiness of the Laestrygonian account, which gave the impetus for our own exploration, may well stem from the unavoidable transmission losses of the spoken word. The fact that it has stayed this way is largely due to its treatment, following rediscovery, as a text frozen in the flow of its form by the authority of age. The illusion of permanence is in reality just a slowness to change. All glaciers move. Some melt.

The Web’s speed, volume and degree of fragmentation make it more than a near-limitless repository of cultural work; it is the most vivid, fluid and comprehensive oral tradition in human history. In the information age, stories and ideas are no longer solitary and sacrosanct gems, but raw materials to be manipulated and re-shaped into new things by an audience that speaks as loudly as any author.

Every story begins its life as a statement; only the successful ones grow into conversations. Whether whispered across a campfire or published electronically to an audience of billions, each telling of a spoken-word story is an impermanent message in a uniquely imperfect, restrictive and (forgive the pun) noisy medium. Giant Cannibals is one small voice in a conversation that’s taken place for two and a half millennia, and “voice” is exactly the right word for what we’re doing.

We've just finished recording Giant Cannibals. After three exhausting days in-studio, I'm delighted to introduce you to our talented and hard-working cast. Expect plenty more to come; in the meantime, you can view their profiles by by following the links. The full list of contributors can also be found in our People section.

Odysseus continues to tell his story. After a brush with the Cyclops, Odysseus' homeward journey is thrown violently off course. Giant Cannibals focuses on this section, because we don't think our hero is telling the truth.